This application relates generally to fans and, more particularly, to fan shrouds for use with fans.
Fan assemblies typically include a fan, a motor, a fan control, and a motor housing. The fan motor and control are positioned within the motor housing and control the energization and rotation of the fan. Because the fan assemblies are often used in applications in which condensation and moisture accumulate, the fan control sometimes fails as a result of exposure to moisture.
To prevent such failures, typically the fan control is covered with a moisture resistant potting material and the motor housing is fabricated with drain holes. However, as air flows over such drain holes, a negative pressure develops within the motor housing that causes air and moisture to be drawn into the motor housing from the environment. Over time, continued exposure to the moisture and airflow causes the potting material to erode, allowing the moisture to contact the fan and motor control. As a result, frequent maintenance is scheduled to prevent such fan assemblies from failing.
In an exemplary embodiment, a fan assembly includes a shroud attached to a motor housing to prevent negative pressure from developing within the motor housing and thus, prevent moisture from being drawn into drain openings. The fan assembly includes a fan, a motor, a motor housing, and a fan control. The motor and fan control are disposed within the motor housing and the fan extends from an upstream portion of the motor housing. The motor housing includes a plurality of drain openings that permit moisture to drain to the environment from the motor housing. The shroud is attached downstream from the fan to the motor housing and is attached co-axially to the motor housing such that the drain openings remain open to the environment.
During operation, air exiting the fan passes over the shroud and is directed downstream. The shroud prevents negative pressure from developing within the motor housing and thus, prevents any moisture from being drawn into the motor housing through the motor housing openings. Additionally, any condensation that develops within the motor housing is permitted to drain through the motor housing drain openings. As a result, a fan assembly is provided that is reliable and cost-effective.